Adolf koepoel



(No Model.)

A.KOEPOEL. ELECTRICAL MEASURING INSTRUMENT. No. 494,961.

Patented Apr. 4, 189.3.

therein S'rATEs- PAT ADOLF Konroat, on BERLIN, RMANY, ASSIGNOR 'ro SIEMENS & HALSKE, l on SAME PLACE.

ELECTRICAL MEASURlNG lNSTRUMENT.

SPEGIFICATIOJST forming part of Letters Patent No. 494,961, dated April 4, 1893. Application filed November'l'i, 1892- Serial No. 452,276. (No model.)

To all whom it may concern: 4 and-5 are respectivelya front elevation and lie known that I, ADOLF KOEPOEL, a suba vertical section of a modification arranged jectot the King of Prussia and German Empefor weak currents. ror, residing at the city of Berlin, Kingdom of In the drawings, 1 O representsa permanent; 5 Prussia, German Empire, have invented new magnet of the horse-shoe type; 11, aconduetor and useful Improvements in Electrical Measthrough which the current to be measured is tiring-instruments, of which the following is carried through the instrument.

a specification. In Fig. 2, the conductor 11 is shown as pro- Myinvention relates to electrical measuring vided with a slot 12, within which the polar 1o instruments. ends of the magnet 10 are located. Measuring instruments for electrical cur- -13 represents a magnetic needle, pivoted rents, whose needle system consists of magat 14 v netized needle, suffer from the disadvantage V 15 is a pointer attached to the needle, and

that the needle is easily demagnetized by too 16 is a scale over which the pointer moves.

strong a current, or is rendered entirely un- The needle 13 is normally held in its zero magnctice Efforts have been made to elimiposition by the infiuenceof the permanent n'ate this defect by replacing the magnetized magnet 10. The current to be measured flows needle by a needle of soft iron, which is magthrough the conductor 11. The lines of force netized from the outside by the influence of produced by the current transmitted through '20 a permanent or an electro-magnet. It is the conductor 11 are perpendicular to the axis found in practice, however, that this arrangeof the magnetized iron needle, inlits position ment is not entirely free from the influence of rest, and therefore produce a deviation of of currents of high potential, as the perma- .this needle, dependentupon the direction and heart magnets employed are magnetized transintensity of thecurrent transmitted, The ex- 2 5 versely by the current to be measured, and tent of the deviationv is measured by the thereby the axis of the magnetic field polarizpointer 15 moving over the empirically iug the needle is reversed,and the zero position marked scale 16. The needle will deviate to of the-needle changed. The sensitiveness of one side or the other of the scale in accordthe instrument is thereby altered, and its inance with the direction of the current trans- 3o dications cannot be relied upon. mitted through the instrument.

My invention consists in a special arrange- It will be observed that the current, in the ment of the magnets polarizing the iron neeconductor 11, flows on both sides of the'legs die, and by reason of this, the detrimentalinof the polarizing magnetandhence the 'curfiuenoe of powerful currents is obviated. rent does not in any wise affect theaction of 35 In my construction, the magnets are placed the magnet, and the instrument, even if travin such a position relative to the conduc irof ersed by abnormally strong currents, does not I the current to be measured that they are 'not lose its sensitiveness. If itis desired that the at nil magnetized by the transmitted current. instrument also be insensible to magnetic in- This client is obtained by causing thev current fluences, independent of those excited hythe 0 to flow in the same direction on both sides of current transmitted, (astatic influences) it is 0 the polar ends of the magnet, so that the magpreferably constructed as shown in Fig. 3,- nctiziug effect of the current flowing in each which is nothing more nor less than a dupliconductcr is compensated on the magnet. cation of theinstr'ument shown in Figs. 1 and In the accompanying drawings which illus- -2, the conductors 11 being so unitedthat they 4 5 trate in y invention, similar figures of referare traversed by the same currentin the same 5 once indicate like parts. direction. In this construction, two needles 13 Figure 1 is a front elevation of a current are shown as mounted upon the same shaft meter, constructed according to myinvention.- l7, and are oppositely magnetized by the relfig. 2 1S avcrtical section. Fig. 3 is also a verspective magnets 1 0, while but'a single pointer 5o tical section,showingamodification: and Figs. 15 is employed, which moves overv thescale 16. The transmitted current always, for reasons which will be readily understood,'turns the two needlesin the same direction.

Figs. 4 and 5 show a measuring instrument for weaker currents, based upon the same principle, which can, for instance, also be used to measure the electromotive force of the'current, It differs from the form shown in Figs. '1, 2, and 3 only in that the partsofi the conductor 11,which1ie to both. sides of the polar ends of the magnet 10, are not located parallel, but follow one another. It is evident that instead of using apermanent- *zzag-aet10, suitably excited electrcmagnets may be employed.

I do not limit myself to the precise construction shown and described as many. changes maybe made therein without departing from the intent of my invention.

1. In a. current measuringinstrument, the combination with a divided conductor, of a magnet having its poles located between the divisions of the conductor, a soft iron needle pivotally supported between the poles of said magneua pointer, and a scale over which the pointer travels.

2. In a current measuring instrument, the combination with a divided conductor, of a magnet having its poles located between the divisions of the conductor, a soft iron noodle pivotally supported between the poles of said magnet and so that the lines of force produced-by the current in the conductor will be perpendicular to the axis of said needle, a pointer, and a scale over-which the pointer travels.

8. In a current measuring instrument, the combination of a magnet,a conductor for con- ,veying the current to be measured located on each side of the poles of said magnet, a soft iron needle pivotally supported between the.

poles of said magnet and normally held in its zero position by the influence of said. magnet,

a pointer, and a scale over which the pointer travels.

4. A current measuring instrument, com prising a magnet, a soft iron needle pivotally supported between the poles of said magnet,

Correction in Letters'Patent No 494,96

i I l Afiidavit having been filed showing that the name of the patentee in Letters Patent No. 494,961, granted April 4, 1893, for an impx oven'lent in Electrical Measuring- Instru'ments should have been Written and printed AdolphKoepks'el instead of Adolph Koepoel, it; is hereby certified that the proper correction has been make in the files;

and records pertaining to the case in the Patent Office, and shouldbe read in the Let ters Patent that the same nay conform thereto. I

Signed, counterslgned, ahd seal ed this 13th day of June, A. D. 1893.

[SEAL] JNO'. M. REYNOLDS,

. Assistant Secretary of the Interior. Uouutersignecl J onN S. SE MOUR,

' Commissioner of 'lavnts. 

